Back in the day (early 70's), I had a few karts, and raced them at a handful of tracks in N. Iowa and S. MN- some asphalt, some dirt. We started on 4-cycle Briggs & Stratton's, but soon graduated to the more powerful 2-cycle McCullough engines. At one 1/2 mile dirt track in MN, a cop clocked me at 90 mph- that's really moving when your butt is sitting about an inch off the ground. Got a handful of trophies, none of which I still have of course.

Not me or my kart(just grabbed this pic on Google),
but very similar to what I had and raced:

Looking back, those Sundays afternoons were an absolute blast. I was wondering if anyone here had ever done this...